scholarly journals A refined bound for the Z1-spectral radius of tensors

Filomat ◽  
2020 ◽  
Vol 34 (7) ◽  
pp. 2123-2129
Author(s):  
Yajun Liu ◽  
Chaoqian Li ◽  
Yaotang Li
Keyword(s):  
Uniform Distribution ◽  
Poisson Distribution ◽  
Spectral Radius ◽  
Gaussian Distribution ◽  
Upper Bound ◽  
Binomial Distribution ◽  
Numerical Experiments ◽  
Applied Mathematics

A refined upper bound for the Z1-spectral radius of tensors is given, which needs less computations than that presented by Wang et al. in [Applied Mathematics and Computation, 329 (2018) 266-277]. Numerical experiments involving Uniform distribution, Gaussian distribution, Poisson distribution and Binomial distribution are given to show the effectiveness of the proposed bound

scholarly journals Effect of zno nanoparticles on diameter of bubbfil PVA/ZnO nanofibers

2015 ◽  
Vol 19 (4) ◽  
pp. 1447-1449
Author(s):  
Cui-Juan Ning ◽  
Hua Liu ◽  
Na Si ◽  
Ji-Huan He
Keyword(s):  
Size Distribution ◽  
Poisson Distribution ◽  
Gaussian Distribution ◽  
Zno Nanoparticles ◽  
Nano Zno ◽  
Fiber Size ◽  
Zno Nanofibers

The PVA/ZnO nanofibers are obtained by the bubbfil spinning. Distribution of fiber size is tenable by nano-ZnO concentration. Experiment reveals fiber size distribution changes from Gaussian distribution to Poisson distribution when ZnO concentration varies gradually from 2 wt.% to 15 wt.%.

scholarly journals Stochastic Flips on Dimer Tilings

2010 ◽  
Vol DMTCS Proceedings vol. AM,... (Proceedings) ◽  
Author(s):  
Thomas Fernique ◽  
Damien Regnault
Keyword(s):  
Fixed Point ◽  
Markov Process ◽  
Upper Bound ◽  
Numerical Experiments ◽  
Triangular Grid ◽  
Expected Number ◽  
Worst Case ◽  
Average Case ◽  
International Audience

International audience This paper introduces a Markov process inspired by the problem of quasicrystal growth. It acts over dimer tilings of the triangular grid by randomly performing local transformations, called $\textit{flips}$, which do not increase the number of identical adjacent tiles (this number can be thought as the tiling energy). Fixed-points of such a process play the role of quasicrystals. We are here interested in the worst-case expected number of flips to converge towards a fixed-point. Numerical experiments suggest a $\Theta (n^2)$ bound, where $n$ is the number of tiles of the tiling. We prove a $O(n^{2.5})$ upper bound and discuss the gap between this bound and the previous one. We also briefly discuss the average-case.

scholarly journals Communication Complexity And Linearly Ordered Sets

2015 ◽  
Vol 29 (1) ◽  
pp. 93-117
Author(s):  
Mieczysław Kula ◽  
Małgorzata Serwecińska
Keyword(s):  
Upper Bound ◽  
Open Problem ◽  
Numerical Experiments ◽  
Communication Complexity ◽  
Ordered Sets ◽  
Finite Sets ◽  
The Family ◽  
Linear Lattices

AbstractThe paper is devoted to the communication complexity of lattice operations in linearly ordered finite sets. All well known techniques ([4, Chapter 1]) to determine the communication complexity of the infimum function in linear lattices disappoint, because a gap between the lower and upper bound is equal to O(log2n), where n is the cardinality of the lattice. Therefore our aim will be to investigate the communication complexity of the function more carefully. We consider a family of so called interval protocols and we construct the interval protocols for the infimum. We prove that the constructed protocols are optimal in the family of interval protocols. It is still open problem to compute the communication complexity of constructed protocols but the numerical experiments show that their complexity is less than the complexity of known protocols for the infimum function.

scholarly journals New Bounds for the α-Indices of Graphs

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1668
Author(s):  
Eber Lenes ◽  
Exequiel Mallea-Zepeda ◽  
Jonnathan Rodríguez
Keyword(s):  
Lower Bound ◽  
Spectral Radius ◽  
Upper Bound ◽  
Adjacency Matrix ◽  
Independence Number ◽  
Minimal Degree ◽  
Diagonal Matrix ◽  
The Matrix

Let G be a graph, for any real 0≤α≤1, Nikiforov defines the matrix Aα(G) as Aα(G)=αD(G)+(1−α)A(G), where A(G) and D(G) are the adjacency matrix and diagonal matrix of degrees of the vertices of G. This paper presents some extremal results about the spectral radius ρα(G) of the matrix Aα(G). In particular, we give a lower bound on the spectral radius ρα(G) in terms of order and independence number. In addition, we obtain an upper bound for the spectral radius ρα(G) in terms of order and minimal degree. Furthermore, for n>l>0 and 1≤p≤⌊n−l2⌋, let Gp≅Kl∨(Kp∪Kn−p−l) be the graph obtained from the graphs Kl and Kp∪Kn−p−l and edges connecting each vertex of Kl with every vertex of Kp∪Kn−p−l. We prove that ρα(Gp+1)<ρα(Gp) for 1≤p≤⌊n−l2⌋−1.

Patterns of macroparasite aggregation in wildlife host populations

Parasitology ◽  
1998 ◽  
Vol 117 (6) ◽  
pp. 597-610 ◽  
Author(s):  
D. J. SHAW ◽  
B. T. GRENFELL ◽  
A. P. DOBSON
Keyword(s):  
Poisson Distribution ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Goodness Of Fit ◽  
Negative Binomial ◽  
Data Sets ◽  
Frequency Distributions ◽  
System A ◽  
Host Sex ◽  
Host Parasite

Frequency distributions from 49 published wildlife host–macroparasite systems were analysed by maximum likelihood for goodness of fit to the negative binomial distribution. In 45 of the 49 (90%) data-sets, the negative binomial distribution provided a statistically satisfactory fit. In the other 4 data-sets the negative binomial distribution still provided a better fit than the Poisson distribution, and only 1 of the data-sets fitted the Poisson distribution. The degree of aggregation was large, with 43 of the 49 data-sets having an estimated k of less than 1. From these 49 data-sets, 22 subsets of host data were available (i.e. host data could be divided by either host sex, age, where or when hosts were sampled). In 11 of these 22 subsets there was significant variation in the degree of aggregation between host subsets of the same host–parasite system. A common k estimate was always larger than that obtained with all the host data considered together. These results indicate that lumping host data can hide important variations in aggregation between hosts and can exaggerate the true degree of aggregation. Wherever possible common k estimates should be used to estimate the degree of aggregation. In addition, significant differences in the degree of aggregation between subgroups of host data, were generally associated with significant differences in both mean parasite burdens and the prevalence of infection.

scholarly journals Comparative Analysis of Median and Average Filters in Impulse Noise Suppression

2014 ◽  
Vol 14 (01) ◽  
pp. 1550002 ◽  
Author(s):  
Luyao Shi ◽  
Yang Chen ◽  
Wenlong Yuan ◽  
Libo Zhang ◽  
BenQiang Yang ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Gaussian Distribution ◽  
Numerical Experiments ◽  
Impulse Noise ◽  
High Efficiency ◽  
Noise Suppression ◽  
High Noise ◽  
Laplacian Distribution ◽  
Distribution Assumption

Median type filters coupled with the Laplacian distribution assumption have shown a high efficiency in suppressing impulse noise. We however demonstrate in this paper that the Gaussian distribution assumption is more preferable than Laplacian distribution assumption in suppressing impulse noise, especially for high noise densities. This conclusion is supported by numerical experiments with different noise densities and filter models.

WELFARE LOSS IN LINEAR PRICE-PREFERENCE PROCUREMENT AUCTIONS

2007 ◽  
Vol 09 (04) ◽  
pp. 719-730
Author(s):  
WINSTON T. H. KOH
Keyword(s):  
Uniform Distribution ◽  
Upper Bound ◽  
Government Procurement ◽  
Welfare Loss ◽  
Procurement Auctions ◽  
Domestic Firms ◽  
Sealed Bid ◽  
Non Linear ◽  
Price Auction

In government procurement auctions, discrimination in favor of one group of participants (e.g. domestic firms, minority bidders) over another group is a common practice. The optimal discriminatory rules for these auctions are typically non-linear and could be administratively complex and costly to implement. In practice, procurement auctions are usually organized as sealed-bid first-price auction with a simple percentage price-preference policy. In this paper, we analyze a model with two bidders that draw their costs from a common uniform distribution, and derive an upper bound to the welfare loss resulting from the use of linear-price preference auctions.

A Simple Modification of the Binomial Distribution

1960 ◽  
Vol 15 (06) ◽  
pp. 436-444
Author(s):  
S. W. Dharmadhikari
Keyword(s):  
Probability Distribution ◽  
Poisson Distribution ◽  
Binomial Distribution ◽  
Probability Distributions ◽  
Simple Modification ◽  
Type Iii

Given any probability distribution, new distributions can be derived from it by assuming its parameters to follow some specific probability distributions. A simple example of this process is provided by the Poisson distributionP(r∣λ) =e-λλr/r! (r= o, 1, 2, …).If the parameterλis assumed to follow the Pearson's Type III lawthen the probability ofrsuccesses is obtained as

scholarly journals Combined Energy Minimization for Image Reconstruction from Few Views

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Wei Wei ◽  
Xiao-Lin Yang ◽  
Bin Zhou ◽  
Jun Feng ◽  
Pei-Yi Shen
Keyword(s):  
Image Reconstruction ◽  
Conjugate Gradient ◽  
Gradient Method ◽  
Energy Minimization ◽  
Numerical Experiments ◽  
Applied Mathematics ◽  
Image Features ◽  
Density Region ◽  
Nonlinear Conjugate Gradient Method ◽  
Nonlinear Conjugate Gradient

Reconstruction from few views is an important problem in medical imaging and applied mathematics. In this paper, a combined energy minimization is proposed for image reconstruction.l2energy of the image gradient is introduced in the lower density region, and it can accelerate the reconstruction speed and improve the results. Total variation of the image is introduced in the higher density region, and the image features can be preserved well. Nonlinear conjugate gradient method is introduced to solve the problem. The efficiency and accuracy of our method are shown in several numerical experiments.

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